The present invention relates to reel pipelaying systems. More particularly, the invention relates to an improved portable reel pipelaying system for use on a variety of water-borne vessels. Still more particularly, the invention relates to improved pipe handling apparatus for such portable reel pipelaying systems.
Historically, the technique of laying undersea fluid-carrying pipelines had its rudimentary beginnings in England in the 1940s. See, e.g., Blair, J. S., "Operation Pluto: The Hamel Steel Pipelines", Transactions of the Institute of Welding, Feb. 1946; and British Pat. No. 601,103 (Ellis), issued Apr. 28, 1948. The concepts described in the Blair article and Ellis patent were used in the wartime operation known as "Operation Pluto", wherein three-inch uncoated steel pipeline was laid across the English Channel. No known further development work or commercial use of the wartime technique of laying pipe offshore from reels was carried out after World War II until about 1960 when research into the reel pipeline technique was renewed by a company in New Orleans, Louisiana. Out of this research came the first known commercial pipelaying reel barge, called the U-303, the substance of which is described in U.S. Pat. No. 3,237,438, issued Mar. 1, 1966, to P. A. Tesson, and assigned, by mesne assignments, to Santa Fe International Corporation, assignee of the invention described herein; see also U.S. Pat. No. 3,372,461 to P. A. Tesson, issued Mar. 12, 1968 as a division of said Tesson U.S. Pat. No. 3,237,438 and commonly assigned therewith.
Tesson was apparently the first to appreciate the necessity for incorporating means for straightening the pipe into the reel pipelaying system in order to make the technique commercially competitive with the traditional stovepiping method of laying pipe offshore. The Tesson invention described in the aforesaid U.S. Pat. No. 3,237,438, combined a pipe straightener and level winder mechanism which was employed for spooling pipe onto the reel evenly and for straightening pipe as it was unspooled. Variations of Tesson's original straightener/level winder have been used with substantially all known subsequently developed offshore reel-type pipelaying systems.
The commercial successor to the U-303 is currently operated by Santa Fe International Corporation in the Gulf of Mexico and is known in the trade as the "Chickasaw"; various aspects of the "Chickasaw" reel pipelaying barge are described in the following U.S. patents, all assigned to the assignee of the invention described herein: U.S. Pat. No. 3,630,461, issued Dec. 28, 1971, in the names of Daniel E. Sugasti, Larry R. Russell, and Fred W. Schaejbe; U.S. Pat. No. 3,641,778, issued Feb. 15, 1972 in the name of Robert G. Gibson; U.S. Pat. No. 3,680,342, issued Aug. 1, 1972, in the names of James D. Mott and Richard B. Feazle; and U.S. Pat. No. 3,712,100, issued Jan. 23, 1973 in the names of Joe W. Key and Larry R. Russell.
Currently in the final construction phases by or on behalf of Santa Fe International Corporation is the first known fully integrated self-propelled reel-type pipelaying ship. The essential features of this new and different vessel are described in U.S. Pat. No. 3,982,402, issued Sept. 28, 1976 in the names of Alexander C. Lang and Peter A. Lunde, and assigned to Santa Fe International Corporation; and in U.S. Pat. application Ser. No. 903,180, filed May 5, 1978 in the names of Charles N. Springett, Dan Abramovich, Stanley T. Uyeda, and E. John Radu; and U.S. Pat. application Ser. No. 903,181, filed May 5, 1978, in the names of Stanley T. Uyeda, E. John Radu, William J. Talbot, Jr., and Norman Feldman. Said Springett et al Ser. No. 903,180 and Uyeda et al Ser. No. 903,181 applications are assigned to Santa Fe International Corporation; the disclosures of each of said Lang et al patent and Springett et al and Uyeda et al applications are incorporated herein by reference as those each were set forth in full below.
The reel-type pipelaying systems described in the several aforementioned commonly assigned U.S. Patents are essentially all of the type which are permanently mounted to a vessel or integrated into the basic construction of a vessel (e.g., barge or self-propelled ship). Another important type of reel pipelaying system is described in U.S. Pat. application Ser. No. 909,260, filed May 24, 1978, in the names of Stanley T. Uyeda and John H. Cha and assigned to Santa Fe International Corporation. Said Uyeda et al application Ser. No. 909,260, the disclosure of which is incorporated by reference herein in its entirety as though set forth in full below, describes a portable reel-type pipelaying system in which the several component parts are unitized for portability. The embodiment of the portable reel pipelaying system described in the Uyeda et al. application Ser. No. 909,260 was designed and constructed for use primarily on supply boats and for operations in relatively shallow waters (up to about 250-400 feet deep).
After the portable reel pipeline apparatus described in the aforesaid Uyeda et al. application Ser. No. 909,260 was first placed into commercial operation off the coast of Australia in about July, 1978, it was discovered that the straightener apparatus thereof sometimes caused buckling of pipe and/or damage to the pipe coating; it was found that due to the profile of the pipe as it came off the reel, the pipe was subjected to excessive loading within the straightener assembly.